The invention relates to a sorting apparatus for sorting out coins from bulk metal as well as to a method for sorting out coins from bulk metal.
It is known that slag from waste incinerators contains coins. To date, these coins have not been sorted out industrially, but are further processed as heavy metal as part of a heavy metal fraction. To be able to sort coins from a metal fraction of a waste incinerator in a cost-effective manner, a corresponding sorting apparatus or a sorting method, respectively, must be able to handle large metal throughputs. In addition, the sorting apparatus must be robust and its purchase and upkeep needs to be cost-efficient. In addition, the coin loss is to be as low as possible.
It is known to recognize coins on a moving belt by means of sensor technology for metal recognition in combination with a camera and to blow them out by means of air nozzles. This method, however, only has net throughputs of less than 100 kg/h with a coin loss of more than 25% and an investment sum of approximately 1 million Euros per ton of throughput.
EP 0 865 005 A1 describes an apparatus for counting and/or sorting coins, wherein the coin sorting apparatus is not suitable for sorting out coins from bulk metal, in particular from a waste incinerator slag fraction. According to the publication, bulk coins, which are more or less correctly sorted, which can partially be contaminated by buttons, staples and paper clips and the like, must instead be placed. The apparatus comprises an inclined conveyor belt as well as a roller, which define a slot between one another. This slot serves to separate the coins. A chute and a coin plate for counting the coins are arranged downstream from the roller in conveying direction.
If bulk metal comprising a comparatively small coin portion were to be supplied in the case of the known sorting apparatus, the apparatus would fail. In particular the throughput would be much smaller than required.
Sorting apparatuses are known from fields outside of the subject area, for example a device for sorting peas according to size from DE 804 493 and a separating apparatus for peeled crabs from U.S. Pat. No. 2,964,181. Both apparatuses are characterized by a conveyor belt, which defines with a roller clearance. The product to be sorted is removed on one side. The known apparatuses are not intended and suitable for sorting coins from a waste incinerator slag fraction.
U.S. Pat. No. 3,004,663 A shows a sorting apparatus from a field outside of the subject area for sorting fruit and potatoes by means of a conveyor belt and rotating rollers. The sorting apparatus is not designed and intended for sorting out coins from bulk metal.